Typically, computer and data storage equipment is housed in standardized equipment enclosures. These equipment enclosures normally comprise an outer, aesthetically pleasing housing which is supported by an inner rack. The rack usually comprises a substantially rectilinear metal frame including several vertical columns each provided with a plurality of mounting and alignment holes which permit the mounting of various equipment hardware to the rack.
The individual equipment components to be mounted inside the equipment enclosure typically are supported by support rails that mount to the columns of the rack. Normally, these rails are screwed or bolted to the rack and the equipment components each placed atop one set of rails. To hold the components in place, the components similarly bolt to the columns of the rack. To further secure the components, usually rear securement clamps are mounted to the rails in abutment to the equipment components to prevent shifting, especially during shipping.
As is known in the art, the support rails typically include alignment tabs adapted to fit within the alignment holes of the rack. Together, the alignment tabs and holes facilitate quick installation of the rails and equipment components by ensuring alignment between the mounting holes provided on the support rails and those provided on the columns of the rack. In conventional systems, the alignment holes are spaced in whole Electronic Industries Association units (EIA-U). The EIA-U is a standardized unit of length equal to 44.45 millimeters. In that conventional support rails are provided with only one set of alignment tabs, the rails can only be attached to the rack in whole EIA-U positions along the rack.
Recently, there have been increased efforts in the industry to maximize equipment storage density in equipment enclosure systems by reducing wasted space with the enclosures. In addition, there has been an effort to provide for online field replacement of equipment component modules such that inoperative or malfunctioning modules can be quickly removed from the rear of the enclosure and replaced without shutting down the system (known in the art as "hot swapping"). The conventional enclosure rack support rail systems described above impede both of these goals.
With regard to storage density, conventional systems prevent maximum utilization of equipment enclosure space because several of the equipment components produced today have non-whole EIA-U dimensions. This creates wasted space within the enclosure in that fractional EIA-U spaces often are left unoccupied. For instance, if a first equipment component is 3.5 EIA-U in height and a second equipment component is 2.0 EIA-U in height, a 0.5 EIA-U of space is wasted if the second component is mounted above the first because the support rails for the second component cannot be mounted to the rack directly adjacent the first component. It can be appreciated that further 0.5 EIA-U spaces are wasted when other whole and non-whole EIA-U height components are installed within the same enclosure. In addition to creating unoccupied areas, these spaces further permit the equipment purchaser to see the unaesthetic rack mounting hardware. Although this hardware can be hidden with front filler panels, this mandates the manufacture and supply of additional parts for the enclosure system.
To remedy these problems, provision of separate whole and half EIA-U support rails has been proposed. Although adequately solving the spacing problem described above, this solution presents the disadvantage of increasing the complexity of planning and ordering enclosed equipment systems and further increases the number of mounting kits that must be stocked by the manufacturer. In another solution, adjustable support rails having elongated adjustment slots have been proposed. Although allowing for fractional EIA-U mounting, these systems present the disadvantages of increasing manufacturing costs and complicating the installation process.
Regarding the hot swapping objective, many conventional systems prevent equipment component modules from being quickly removed and replaced in that rail side flanges typically are required to retain conventional rear securement clamps. These return flanges intrude inwardly into the horizontal equipment envelope of the enclosure to prevent the individual equipment component modules from being removed. Accordingly, the entire component must be removed from the front of the enclosure before the module can be replaced, requiring system shut-off therefore resulting in system down-time.
From the above, it can be appreciated that it would be desirable to have an equipment enclosure rack support rail system which solves the above-identified problems.